Posts Tagged → timeline

A look at how Instagram works. Instagram serves billions of users a feed that’s the textbook example of the “fanout-on-write” pattern, with a hybrid escape hatch for celebrities. The architecture that’s survived a decade of feature growth is built on one decision: each user gets a pre-materialized timeline in Redis, updated whenever someone they follow… Continue reading →

A look at how Twitter timeline works. Twitter’s timeline is the architecture every feed product gets compared to, because Twitter’s engineering team published the most honest write-ups of the trade-offs. The headline pattern is hybrid fanout: write-time fanout for normal users, read-time fanout for celebrities, merged on every read. The cutover threshold is the most-tuned… Continue reading →